If you really care about your friend better to tell him everything, and teach them how to play in the market. Im not saying that you idea is illegal, its legal as long as you are committed but again teaching him about cryptocurrency is the best thing that you can do, let him enjoy the cryptomarket.
really, better to give a little direction and start sharing knowledge, it's more useful than we buy for others, because a science can produce many benefits rather than just buying, sharing with others will give us many advantages, in bitcoin all can be interrelated, especially the existence of important information sharing, can change the perspective of the general public.